Device for biological purification of waste water



FIG. 1 is a first side view of a device for biological purification of waste water in accordance with my design;

FIG. 2 is a second side view of the device for biological purification of waste water in accordance with my design;

FIG. 3 is a third side view of the device for biological purification of waste water in accordance with my design;

FIG. 4 is a bottom plan view of the device for biological purification of waste water in accordance with my design;

FIG. 5 is a top plan view of the device for biological purification of waste water in accordance with my design; and

FIG. 6 is a fourth side view of the device for biological purification of waste water in accordance with my design; and,

FIG. 7 is a perspective view of the device for biological purification of waste water in accordance with my design. 

The ornamental design for device for biological purification of waste water, as shown and described. 